1. Field of the Invention
This invention relates to an improved track roller device.
2. Description of the Prior Art
The oil supply system of a conventional track roller device will be hereinafter described with reference to FIG. 5, which is an elevational sectional view of a conventional track roller device with the upper half in section.
As shown in FIG. 5, a conventional track roller device is produced by molding a one-piece casting containing left and right rollers 120c and 130c, or by separately molding the left and right rollers 120c and 130c and then fixing them together, such as by welding. Therefore, in the case of the conventional device, rollers such as single-flange rollers and double-flange rollers cannot be selected at will for assembly. When a part of the rollers 120c and 130c becomes worn, typical repair procedures include replacement of the entire roller device or padding of the worn parts with a hard alloy for reuse. The former procedure is very expensive and uneconomical and the latter procedure is time-consuming and requires discontinuing operation of the roller device for a long time. Since the rollers in the conventional device are integrally formed with each other, the oil supply system is very complicated and therefore the operational efficiency of the oiling procedure is extremely poor. A central passage 30c is provided in the shaft 40c and extends axially from one end thereof. Radial passages 33c and 34c are provided in the shaft and extend from the central passage 30c to the oil chambers 21c and 22c, respectively. Inside cylinders 50c and 60c are fitted between the outside surface of shaft 40c and the inside surfaces of the rollers 120c and 130c. Recesses 54c and 64c are provided on the outside surfaces of the inside cylinders 50c and 60c. At the bottoms of the recesses 54c and 64c, there are provided radial passages 55c and 65c leading to the outside surface of the shaft 40c and axial passages 56c and 66c leading to the oil chambers 21c and 22c. A plug 35c is screwed in the central passage 30c from one end thereof.
As a result, in the case of the conventional device, the provision of deep and long passages is very difficult and very expensive. In addition, oil must be supplied from above, with the shaft 40c kept vertical, and therefore the operating efficiency is poor and a desired amount of oil cannot be fully supplied to the portions that require lubrication.